Vulnerability to Climate Change: Water Resource Stress and Food Insecurity in Southern Africa

According to the Intergovernmental Panel on Climate Change, climate change will disproportionately
affect the most vulnerable populations in the developing world. Rising temperatures, increasingly
severe floods and droughts, and sea-level rise threaten economies that are reliant on agriculture,
in countries whose governments lack adaptive capacity, and in areas where populations have little
access to healthcare and education.

A graduate student research team working with the Climate Change and African Political Stability
(CCAPS) program used Geographic Information Systems (GIS) to identify the regions at greatest
risk across Africa.1 This regional study on southern Africa includes Angola, Botswana, Lesotho,
Madagascar, Malawi, Mozambique, Namibia, South Africa, Swaziland, Zambia, and Zimbabwe. This
study examines the potential impact of a confluence of factors on countries’ overall vulnerability
and their ability to minimize the effects of climate change.

This study focuses in particular on resilience to stress on water resources, considering southern
Africa’s dry climate and reliance on transboundary river basins and groundwater for agriculture,
industry, and consumptive use. The study also focuses on water resource management institutions
and governments’ capacity to respond to changes in rainfall patterns. Droughts in the region are
becoming longer and more severe, while rainfall patterns vary greatly, leaving farmers less able to
predict harvests. Floods are made worse by drought-stricken land’s inability to absorb heavy rains,
which causes runoff and flash floods. Combined, the severe drought-flood cycle can destroy crops
quickly and cause permanent soil degradation that results in long-term declines in agricultural
output.

The areas in southern Africa that will be most affected by climate change are identified using a
variation of the CCAPS vulnerability assessment model.2 The model for southern Africa measures
climate change vulnerability by examining five main sources or “baskets” of vulnerability:
population density, historical exposure to climate-related hazards, household and community
vulnerability, governance, and resilience to stress on water resources. These sources of vulnerability
are described as “baskets” since they typically each contain multiple indicators.

Climate change will have the largest impact on areas that have high population density, significant
historical exposure to climate-related hazards, high household vulnerability, poor governance,
and low resilience to stress on water resources. Population density is included because of the
study’s concern with where and how climate change will affect people. Historical exposure to
climate-related hazards—including floods, droughts, cyclones, and fires—is used as an indicator of
possible future exposure to climate change. The household and community vulnerability basket
is made up of health and education indicators, and is included to measure a population’s ability to
respond to climate crises. Where governance is poor, it is expected that the government’s inability
or unwillingness to minimize risk to the population will exacerbate the effects of climate change.
Finally, the resilience to stress on water resources basket measures a country’s ability to manage
changes in rainfall patterns based on current levels of water availability and use, the population’s
access to improved drinking water, and dependency on water from other countries. These five
baskets together constitute the composite vulnerability model used in this study on southern
Africa. This is used to identify the areas of southern Africa that are most vulnerable to the impacts
of climate change.

According to this model, the most vulnerable parts of the region are Zimbabwe, Madagascar,
and the southeastern coast of Africa. Zimbabwe is extremely vulnerable, largely due to its poor
governance and extreme flood and drought cycles. Madagascar’s vulnerability can be attributed to
its poor scores on household and community indicators and its susceptibility to cyclones from the
Indian Ocean. Much of the region’s most vulnerable areas lie within the Zambezi River basin; this highlights the importance of examining water resource management and shared water supplies for
evaluating climate change impacts. Countries will have to assess their own institutional weaknesses,
work with neighboring governments to design effective water management agreements, and
coordinate responses to climate-related disasters.

Climate change is expected to cause increasingly severe floods and droughts in the southern
Africa region, threatening the reliability of agricultural output and increasing the risk of food
insecurity. This is both an immediate and a long-term concern, and future research should focus
on connections between protracted food insecurity and varying degrees of conflict. While the
findings of this paper show that large areas in southern Africa are extremely vulnerable to climate
change and could face serious food insecurity in the near future, responsible water management
in the region could lessen the risk of severe shortages. The southern Africa region is home to
11 transboundary river basins, making international cooperation over the equitable allocation,
sustainable use, and efficient distribution of water resources key to the region’s ability to manage
the impacts of climate change on populations and economies.